A variety of hormonal abnormalities have been described in women with anorexia nervosa. Two abnormalities which probably reflect a hypothalamic disturbance are age-inappropriate, immature circadian patterns of luteinizing hormone secretion and increased levels of adrenal activity. However the nature of the association between these endocrine abnormalities and the syndrome of anorexia nervosa is obscure. These endocrine disturbances may be specific hallmarks of the syndrome of anorexia nervosa or may be non-specifically associated with individual features of this syndrome, such as weight loss. We propose to examine the association between anorexia nervosa and these hormonal disturbances by conducting studies of hypothalamic-pituitary-ovarian and hypothalamic-pituitary-adrenal activity in women who do not have the full syndrome of anorexia nervosa but who do exhibit one or several features of the syndrome. For example, we propose to study women of low body weight who do not show distorted body image or obsessive preoccupation with food and weight. If such women are found to have the same types and degrees of hypothalamic-pituitary-ovarian and hypothalamic-pituitary-adrenal dysfunction as women with anorexia nervosa, we can conclude that these endocrine disturbances are not unique to the syndrome of anorexia nervosa but are related to the non-specific feature, namely low body weight. The clinical features we will focus on are decreased body weight, disturbed eating behavior, distortion of body image, increased physical activity and acute psychological stress. We will use psychological and behavioral ratings and several measures of hypothalamic-pituitary-ovarian and hypothalamic-pituitary-adrenal activity.